As a follow up to the post highlighting the CHAMACOS Study on the impact of pesticides on the children of California, I thought it would be a fine idea to gather some informative readings on pesticides.

From infancy on, the children of the mothers with the highest levels of organophosphates were at the greatest risk for neurodevelopmental problems. That association was present at every stage the researchers checked in on the kids. At 6 months, they were more likely to have poorer reflexes. At 2, they were at higher risk for pervasive developmental disorder, an autism-related condition, like Asperger’s, in which children have trouble connecting to others. At 5, they were more likely to be hyperactive and have trouble paying attention. At 7, they scored lower on IQ tests, by an average of seven points—the equivalent of being a half-year behind their peers. Eskenazi can’t say whether the associations persist, because she hasn’t been funded to keep looking.

One of the best ways to look at what is being used in both conventional and organic farming is to look at the extensive and transparent, California Pesticide Information Portal (CalPip). California has a tremendous diversity of crops and also a very large share of the organic market. It is a source for data which comes from mandatory reporting of all commercial pesticide use in the state. CalPip posted two lists of the top 100 pesticides used – one based on total pounds applied and one based on the total number of acres treated. I created a list that combined the two without the surfactants or other spray additives. That left 104 materials. I then looked up the publicly available, MSDS documents (Material Safety Data Sheets) to get the acute toxicity (oral ALD50) for each of the products (see graph below).

They grow a crop as best they can, and use pesticides only as necessary and within the strict rules established by the EPA. Much of what they use are pesticides with very low toxicity. In years that their crop is selected for the PDP, random samples of their commodity are purchased in stores, including examples coming from other countries. They are taken to federal and state laboratories and scrutinized for trace residues of hundreds of different chemical pesticides. When the data is finally published (usually two years later), the highly qualified experts of the USDA, EPA and FDA conclude that the system is working and that consumers should confidently purchase and eat the crop without concerns about residues. In fact, studies show that the anti-cancer benefits of eating things like fruits and vegetable far, far outweigh and minuscule risk associated with pesticides.

Then each year, the EWG takes advantage of the transparent availability of the USDA-PDP data, but then performs their own “analysis” which experts have rejected as utterly anti-scientific. They generate an incorrect “grade” for the crop and post it as part of their “Shopper’s Guide,” and on their notorious “Dirty Dozen List.” The grower’s virtually perfect grade gets forgotten and what is passed along by an un-critical press and blogosphere is the distortion that the crop is “dirty.” Many consumers believe this and heed the EWG’s suggestion that they need to buy organic versions of that crop (the actual agenda of the EWG is the promotion of organic and also their own fundraising). Worse still, there is some evidence that this disinformation causes consumers to purchase and eat less produce. At a minimum, many consumers feel guilty for not buying organic.

Figure 4 shows the difference in herbicides between 1995 and 2007. Peak applications are in May, as expected. What you see is that glyphosate becomes the main herbicide detected. What the activist literature does not bother to tell you is that the increase in glyphosate substitutes for “other herbicides”. Atrazine levels decreased 36%. Trifluralin was present in almost every sample but its levels were 20 times lower than 1995. Essentially, glyphosate removed the need for other herbicides with higher environmental impact, a fact well documented (e.g. Duke et al., 2012).

Concentrations? Oh, and don’t forget to look at the y-axis units. We’re dealing with nanograms per cubic meter. Considering these compounds are biologically relevant at the conservative level of milligrams per kilogram, we’re talking about levels millions to billions of times below any biological relevance.

. . . Here’s another set of data that the dirty green media forgot to report, but more likely they didn’t read it because it was not in the abstract. The trend from 1995 to 2007 shows a decrease in insecticide use. In 1995 methyl parathion was heavily used in Mississippi on cotton (160,000 kg!). By 2007 its levels dropped twenty fold. In 1995 there was high reliance on Chlorphyifos and malathion, and by 2007 the levels were down substantially, the authors citing ”no local use”. All “other insecticide” levels were lower as well.

Why? Why the decrease between 1995 and 2007?

The introduction of transgenic (GMO) Bt cotton and Bt corn, the two principle crops of the region.

The 2008 report GM crops: global socio-economic and environmental impacts 1996- 2006 (pdf) produced by PG Economics did answer these questions*. They used an index called EIQ (Environmental Impact Quotient) which was first described by Kovach et al in 1992 (to learn exactly how the EIQ is calculated, see the American Farmland Trust’s explanation). The EIQ actually factors in how toxic a pesticide is as well as how much active ingredient is used. This report found (on page 60-61) that, in soybeans, the global impact has been:

In 2006, a 6% decrease in the total volume of herbicide [active ingredient] applied (10.1 million kg) and a 23.7% reduction in the environmental impact (measured in terms of the field EIQ/ha load)

Since 1996, 4.4% less herbicide [active ingredient] has been used (62 million kg) and the environmental impact applied to the soybean crop has fallen by 20.4%.

A similar global impact was seen in maize:

In 2006, total herbicide ai use was 8.3% lower (10.9 million kg) than the level of use if the total crop had been planted to conventional non GM (HT) varieties. The EIQ load was also lower by 10.8%

Cumulatively since 1997, the volume of herbicide ai applied is 3.9% lower than its conventional equivalent (a saving of 46.7 million kg). The EIQ load has been reduced by 4.6%.